使用 Heroku Scheduler 运行一个简单的 Java HelloWorld

Question

I want to run a simple program -- like HelloWorld -- on Heroku, and also using Heroku Scheduler to run each 10minutes.

I`m not sure about Maven-pom.xml setting, Heroku run task system, and Heroku Scheduler.

Now I have these source but the task result is failed.

> MyApp.java
package com.github.graycat27.sample
public class MyApp {
   public static void main(String[] args){
      System.out.println("Hello Heroku Scheduler task!");
   }
}

> pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.github.graycat27</groupId>
    <artifactId>MyApp</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    </properties>
</project>

> Heroku Scheduler job command
$ java MyApp

deploy to Heroku via GitHub has completed in success.

as a result, logs shows

2021-07-21T11:13:59 app[api]: Starting process with command `java MyApp` by user scheduler@addons.heroku.com
2021-07-21T11:14:02 heroku[scheduler.5096]: Starting process with command `java MyApp`
2021-07-21T11:14:03 heroku[scheduler.5096]: State changed from starting to up
2021-07-21T11:14:05 app[scheduler.5096]: Picked up JAVA_TOOL_OPTIONS: -Xmx300m -Xss512k -XX:CICompilerCount=2 -Dfile.encoding=UTF-8
2021-07-21T11:14:05 app[scheduler.5096]: Error: Could not find or load main class MyApp
2021-07-21T11:14:05 heroku[scheduler.5096]: Process exited with status 1
2021-07-21T11:14:05 heroku[scheduler.5096]: State changed from up to complete

what should I change my program or config?

Answer 1

您的 ClassName 不是MyApp它的com.github.graycat27.sample.MyApp并且您需要提供它可以在 Class-/Module-Path 上找到此文件的位置